To form a seal between a roof and a pipe projecting through this roof, it is known to construct roof flashing structures of the type having a flat plate which has a centralized opening and an upstanding tapered housing attached to the flat plate and extending around said opening. The opening between the housing and the pipe is then sealed with a calking or other mastic-like material which with time and weather will frequently crack and/or deteriorate to such an extent that it will leak.
In my U.S. Pat. No. 4,010,578 I described certain roof flashing structures which incorporate the use of a sealing ring to overcome the disadvantages of the prior flashing structures. However, even with the advantages of my prior roof flashing structures it is considered that there exists a need for a roof flashing structure of the type incorporating a sealing ring wherein said sealing ring is fixed in place in the roof flashing structure and cannot be easily disengaged from said structure and become lost during transit and storage, in addition to a roof flashing structure having a sealing ring which is held fast to the flashing structure so that when a pipe is pushed up through the sealing ring the sealing ring is maintained in its proper sealing position within the roof flashing structure and is not pushed out of the structure or the seal between the housing and the ring distorted by the action of the pipe through the ring.